1. Field of the Invention
The subject invention relates to hair cutters for use at home and elsewhere which may be safely used by men, women and children for hair cutting, trimming and/or grooming. The subject invention has particular utility when modern hair styling techniques are employed and precise blade control is an important requirement.
2. Prior Art
In U.S. Pat. No. 2,731,717, Abram N. Spanel, a co-inventor of the subject invention, disclosed various embodiments of a hair cutter which two decades ago were a commercial success. However, in today's society, with ever increasing emphasis placed on consumer protection, the safety of such a hair cutter has become of critical importance and must receive as much attention as the operability of the device. Furthermore, current difficulties of acquiring certain materials require modifications consistent with providing a durable product.
The preferred embodiment of aforementioned U.S. Pat. No. 2,731,717, included a cage formed by a plurality of tines within which was located a laterally adjustable cutting blade. The blade was adjusted by means of a thumb wheel which was carried by the handle portion of the cutter.
In the preferred embodiment of U.S. Pat. No. 2,731,717, as shown in FIG. 2, a gap was provided in the tines, between clamp plates 31 ad 32, to allow access for blade changing purposes. To accomplish this, a clamping element had to be unlatched and the blade physically guided through the gap in the cage. The task of inserting the new blade was complicated by the restricted finger space around the clamping means and considerable dexterity was required to properly secure the blade. Handling blades under these circumstances created a safety hazard that detracted from the appeal of the device.
While FIG. 6 of the aforementioned U.S. Pat. No. 2,731,717 disclosed a removable cage, which was intended to lessen the difficulty of blade changing, the effect was to increase danger by permitting the blade to be completely exposed in a mounted condition making accidental contact, including a sliceable contact with one of the cutting edges a distinct possibility. The cutting device of FIG. 6 was considered to not provide adequate safety for commercial production when the original commercial embodiment was selected and today's safety standards further lessen the attractiveness of that particular device.
In U.S. Pat. No. 3,855,696, an improved hair cutter is disclosed in which safety requirements are properly and humanely emphasized. Longitudinal movement of either the blade carriage or the cage is provided to eliminate the necessity of reaching inside of the cage to clamp and unclamp the blade. Regardless of whether the cage is moved to expose the blade carrier or the blade carrier is slid longitudinally to extend outwardly of the cage, a shielding member 16a occupies a central position and is dimensionally wider than the cutting blade, thus preventing injurious contact with its cutting edge or edges when the blade is in its centered position. The relative logitudinal movement between cage and blade carrier is permitted by a safety mechanism only when the blade is in its shielded position. In one embodiment, structure is disclosed to prevent accidental lateral shifting of the blade and its cutting edge or edges away from its shielded position when the cage is removed; and only by replacing the cage can further lateral adjustment of the blade occur.
In Ser. No. 450,581, which is a continuation-in-part application of U.S. Pat. No. 3,855,696, a further modified embodiment is disclosed. The cage is supported in such manner as to be longitudinally adjustable to expose the blade for unobstructed access thereto, thus facilitating blade changing without complete removal of the cage. This modification eliminates the need to rejoin the cage to the frame, which might prove perplexing to some users, such as those who are accident-prone.
While these recent disclosures provide distinct advantages over the earlier models, due consideration of current manufacturing problems has resulted in further invention, disclosed herein, in which simplicity without sacrifice of improved safety features becomes possible, thus meeting requirements for a successful commercial embodiment.